Residue Dynamics and Risk Assessment of Trifloxystrobin and Tebuconazole on Tomato (Lycopersicon esculentum Mill.)

The study was undertaken to determine the dissipation kinetics of trifloxystrobin and tebuconazole residues on tomato under field conditions and thereby to ensure consumer safety. Three applications of a combination formulation, Nativo 75 WG (trifloxystrobin 25% + tebuconazole 50%) were made @ 350 and 700 g ha-1 at 7 days intervals. Tomato samples were collected at 0 (1 hr), 1, 3, 5, 7, 10 and 15 days after the last application. The average initial deposits of trifloxystrobin on tomato fruits were found to be 0.40 and 0.76 mg kg-1, and that of tebuconazole were 1.56 and 2.76 mg kg-1, at single and double dose, respectively. Half life of trifloxystrobin were observed to be 1.39 and 1.94 days, at single and double doses, respectively, whereas with respect to tebuconazole, these values were 0.93 and 0.78 days. Soil samples collected after 15 days did not reveal the presence of trifloxystrobin, its metabolite CGA321113 and tebuconazole at their detection limit of 0.05 mg kg-1. Theoretical maximum residues contribution (TMRC) for trifloxystrobin and tebuconazole were calculated and found to be well below maximum permissible intake (MPI) on tomato at 0-day (1 hr after spraying) for the both the test doses. Thus, the application of combination formulation Nativo 75 WG (trifloxystrobin 25% + tebuconazole 50%) at the recommended dose on tomato did not seem to pose any human health risk.